Switches are used in electrical applications to selectively provide an electrical connection between two or more terminals of a respective switch. Power switches are used in applications where high voltages have to be switched and/or high currents have to be conducted via the switch, for example voltages of hundred Volts or more and currents of several Amperes, for example several tens of Amperes. Such switches may inter alia be used in safety-critical environments, for example in automotive applications. In such environments, besides the “pure” function of a device like a switch (that is selectively providing an electrical connection), functional safety aspects become more and more important, for example in automotive applications in the power transmission chain, braking, engine management etc.
For example, according to some functional safety requirements, for a specific function there may have to be alternative ways to achieve this function, and/or a safe switch-off path to deactivate the function. In some cases, in order to achieve this, redundancy may be provided, for example alternative connections between devices, or different ways to achieve a function may be provided, which is an example for diversification (sometimes also referred to as diversity). To give an example, in conventional systems to control a switch or combination of switches (for example arranged in a half-bridged topology), in some applications two signal paths are required: one to define a switching behavior of a switch (for example by providing a pulse width modulated (PWM) signal), and another one to enable/disable the operation of the switch or combination of switches. These two signals are generated and provided by different paths. However, in conventional approaches the signal paths are merged before a single control signal is provided to the switch. When a signal path used to transmit the single control signal is broken, the switch may enter an undesired or undefined state or may otherwise exhibit an erroneous behavior. In safety-critical environments, it is often desirable to be able to at least detect such an erroneous state.